1. Field of the Invention
This invention relates to air conditioning coils that are associated with the discharge side of a heating furnace.
2. Background Art
Conventionally, the conditioning of air (“air conditioning”) includes not only its cooling but also the heating of air, cleaning it and controlling its moisture level. Air conditioning typically occurs in heating, ventilation, and air conditioning (HVAC) equipment.
The Department of Energy (DOE) has imposed minimum efficiency requirements for residential-light commercial HVAC equipment. In response to standards derived from the National Appliance Energy Conservation Act (NAECA) and to meet the challenges imposed by the federally-mandated standards, manufacturers seek ways to produce more efficient equipment, while making that equipment available to the consumer or user at an affordable pricing structure. One consideration is the consumer's life cycle cost for equipment that operates at various efficiency levels. At issue, for example, is whether a high-efficiency system can be justified to home owners in northern states and whether such systems would operate long enough to offer a reasonable payback.
To accomplish air conditioning tasks, conventional air conditioning systems include five components: (1) a compressor; (2) a fan; (3) a condenser coil (hot); (4) an evaporator coil (cool); and (5) a chemical refrigerant. In a conventional air conditioner, a refrigerant like liquid ammonia or Freon® is the coolant. As used herein, the term “Freon®” is generically used for any of various non-flammable fluorocarbons used as refrigerants.
It is generally understood that the efficiency of an air conditioning system can be raised by adding to the face area of a coil. But historically, expanding the face area of the coil has produced coils that are too large to meet the spatial constraints imposed by the environment of use. Typically, coils are accommodated by housings that are tailored to satisfy industry or residential needs. Often, the space allocated in a building to the installation of a housing with coil therein is a relatively small space that is limited by walls and ceilings. One consequence is that enlarged coils (sized for efficiency) cannot be accommodated.
Another factor to be considered in designing efficient HVAC equipment is coil orientation, which may also be limited by the shape of drain pans that are needed to collect condensate.
There has thus arisen a requirement for coils with expanded face areas for air conditioning systems that can usefully be deployed in existing housings and installation sites, that are not limited to a single orientation. Additionally, there is a continued desire for suitable drain pans that can serve coils which may be deployed in various orientations.
Furthermore, it is desirable that such systems be simple to install and readily fabricated, while not being too difficult to access for repair and maintenance.
The following U.S. references were identified in a preliminary search that preceded the filing of this application: U.S. Pat. Nos. 2,959,031; 5,121,613; 5,207,074; and 5,284,027.